Happens with imported decks with a deck image. As soon as the world is left, next time the deck is pulled from the Journals the deck image is gone. Does not happen to decks already placed on the canvas, those keep their deck image.
The best way of doing this as a workaround is to double-click the deck tile itself in the canvas, and set the image to what you want just like any other tile.
Happens with imported decks with a deck image. As soon as the world is left, next time the deck is pulled from the Journals the deck image is gone. Does not happen to decks already placed on the canvas, those keep their deck image.
Foundry 0.8.7 DnD5e 1.3.3 Card Support 1.6.1